Carriage rebound checking device



June 26, 1951 BECKER 2,558,413

CARRIAGE REBOUND CHECKING DEVICE Filed Dec. 50, 1948 2 Sheets-Sheet 1 INVEN TOR. FRED BECKER ATTORNEY June 26, 1951 I F. BECKER 2,558,413

CARRIAGE REBOUND CHECKING DEVICE Patented June 26, 1951 CARRIAGE REBOUND CHECKING DEVICE Fred Becker, Queens Village, N. Y., assignor to Underwood Corporation, New York, N. Y., a corporation of Delaware Application December 30, 1948, Serial No. 68,322

6 Claims. (Cl. 197-176) This invention relates to the tabulating mechanism of a typewriter and in particular to a rebound check to prevent rebound of the carriage at the end of a tabulating run.

The invention has for one of its objects the provision of a simple, reliable and inexpensive mechanism which will prevent a rebound of the carriage from the tabulator stop at the end of a tabulating run of the carriage.

Another object of the invention is the provision of a carriage rebound checking device which is normally free of the carriage so as to offer no interference thereto and which is brought only momentarily into an active position by the restoration of the carriage tabulating mechanism.

It is also an object of the invention to prevent an incorrect positioning of the typewriter carriage as a result of the rebound of the carriage from a set tabulator stop reed at the end of a tabulating run by means of a rebound latch urged into engagement with the carriage solely by reason of the inertia of the parts of the latch.

Other objects will be in part obvious and in part particularly pointed out in the following detailed description of one embodiment of the invention and in the appended claims.

In the drawings showing one of the possible embodiments of the invention:

Figure 1 is a sectional side view showing the power-operated tabulating mechanism and the rebound check device in their normal positions,

Figure 2 is a rear view of the carriage rebound check device showing the manner of its attachment to the typewriter,

Figure 3 is a top view of the parts shown in Figure 2,

Figure 4 is a detail view from the rear showing the position of the tabulator stop reed of Figure 1,

Figure 5 is a side sectional View showing part of the structure of Figure l in the position assumed when the tabulating mechanism is actuated,

Figure 6 is a detail top view showing of a portion of Figure 3 showing the position of the rebound check pawl during a tabulating run as in Figure 5,

Figure 7 is a detail view similar to Figure 4 showing the operated position of the tabulator stop reed,

Figures 8, 9 and 10 are views similar respectively to Figures 5, 6 and 7 but showing the 1305i tions of the parts at the end of a tabulating run of. the carriage, and

Figure 11 is a perspective View of the rebound checking device.

The typewriter to which the invention is applied is the well-known Underwood Electric typewriter and for that reason no general description of the machine need be given. The tabulating mechanism disclosed herein. is substantially similar to that disclosed in U. S. Patent No. 2,303,878, which issued to W. F. Helmond on December 1, 1942. This mechanism will be only briefly described herein, reference being made to said patent for further details of this well-known structure.

General Description The typewriter to which the present invention is applied includes a carriage l5 of the usual design freely slidable in grooves IS in the typewriter frame 23. A spring drum ll on frame 23 is connected by a flexible tape l8 to carriage l5 to urge the carriage to the left of the operator. A rack IS on carriage |5 is normally engaged with an escapement controlled pinion 20 on a shaft 46 to restrain the carriage l5 against the drive of spring drum I1 and to permit the normal letter feed movement of carriage |5 during typing operations.

A tabulatlng mechanism is provided to release carriage l5 from the normal restraint of the escapement mechanism and to interpose a stop into the path of carriage I5 to arrest carriage 5 at a new leftward position. This tabulating mechanism comprises, as shown in Figure 1, a tabulating key 2| pivoted on a rod 22 fixed in a frame member 23. An interponent 24, also pivoted on frame member 23, is engaged between the tabulator key 2| and a tabulator action lever 25 to transmit motion from key 2| to lever 25. A hook 26 is slidably and pivotally mounted on lever 25 and is tensioned to be normally in engagement with a lug 21 on a tabulator actuator bar 28. Actuator bar 28 is pivoted at its forward end to a sub-lever 29 carried by the frame 23 and carries near its rear end a pawl 30 which is engageable with a constantly rotating snatch roll 3| by a depfession of key 2| acting through the members 24', 25 and 26 to lower the rear end of actuator bar 28. Engagement of pawl 30 and snatch roll 3| will cause an immediate forward stroke of actuator bar 28 which stroke continues until a lug 35 on the rear end of actuator bar 28 is engaged by a tooth of snatch r011 3|. Further r'o tation of snatch roll 3| will elevate the rearward end ofbar 2-8 to disengage pawl 30 from snatch roll 3| and permit a restoring spring 36 to immediately return bar 28 to its normal position as in Figure l.

The forward stroke of actuator bar 28 is com municated by an interponent 81 to an arm 38 on a shaft 39 to rock the latter counterclockwise. Another arm 49 on shaft 39 is connected by a link 4| to a lever 42 pivoted near the rear of the typewriter. As more fully disclosed in Patent No. 2,303,878 above mentioned, the carriage I5 and escapement wheel shaft 46 connected thereto by pinion 28 and rack l9 are, upon operation of shaft 39 and lever 42, freed from the restraint of a conventional escapement mechanism, not shown in detail, by a lever 4! connected between the forward end of lever 42 and apart of the escapement mechanism. Counterolockwise rocking of lever 42 also projects the upper end of a tabulator reed 48'connected by a pivot pin 65 to the rear end of lever 42 into the path traveled by a set one of the settable tabulator stops 49 on the rear of carriage I5. The tabulator stops are vertically slidable in the usual tabulator rail 59 and are downwardly settable to an effective position by a manually operated finger 5! in the usual man-,

ner.

Shaft 39, lever 42 and tabulator reed 48 are retained in their operated positions by a latch lug 52 fixed near the top end of reed 48 which lug 52 H is, in the operated position of reed 48, raised above a plate 53 fixed to the upper part of the tabulator reed housing 55, see Figures 2 and 7, and drawn, as shown in Figure '7, into latchin engagement therewith by a spring 54 connected between the reed 48and a part of the housing 55. Actuator bar 28 is free to be'returned to its normal position by its restoring spring 38 despite the latching of shaft '39 and its connected parts in their actuated positions, by reason of the pin and slot connection between actuator 28 and interponent 31.

The latched parts are released from their actuated positions by the engagement of a set carriage stop 49 with the upper end of tabulator reed 48. Such engagement will move the upper end of reed 48 to the right, Figure 10, and thereby move lug 52 from engagement with plate 58 to free reed 48 to the action of a reed restoring spring 56 connected between the reed 48. and the lower part of the housing 55. Reed 48 in its return to normal position, restores levers 41, 42 and shaft 39 to their rest positions, as shown in Figure 1, lever 47 concurrently reengag'ing the escapement mechanism to restrain the carriage I5 in its adjusted position.

Tabulato'r rebound check A tabulating mechanism of the type above described does not under certain conditions always lator reed 48 is released from latch plate 52 when the carriage I5 is first arrested and immediately reengages the escapement mechanism pawls with the escapement wheel, the carriage I5 after such a rebound, stops in a position one or more letter spaces to the right of the intended position.

The novel mechanism of the present disclosure has been devised to prevent an incorrect tabulation due to such rebound of the carriage from the tabulator reed 48. The rebound check is free of the carriage I5 at all times except immediately after a tabulation when it is moved to momentarily engage a stop 49 on the tabulator rack 50. The rebound check device is pivota y mounted on a bracket 59, Figure 2, fixed to the rear of the tabulator housing 55. The rebound check comprises a U-shaped frame 60 pivoted to the ends of bracket 59 by screws 5|. The lower bar of frame 58 is flanged downwardly, see also Figure 11, and has secured thereto an arm 62 to which is fixed a weight 88, the weight 63 being carried rearwardly of the vertical plane through the pivots 8i and tending to rotate the frame 60 clockwise about its pivots 8|. Adjustably secured to the forward end of arm 82 is, a nose 64 which will, in the normal position of the parts, be pressed by the action of weight 63 against the pin 65 forming the connection between lever 42 and tabulator stop reed 48.

The left arm of frame 38 is extended upwardly and formed into a stop nose 58, Figure 11, which may be engaged with the top of the unset tabulator stop 49 to the left, Figure 3, of the set stop 49 which engages tabulator stop reed 48. A support 8'! for stop nose 89, Figure 2, is adjustably secured to a bracket 68 extending from the tabulator housing 55 and is positioned to the left of stop nose 98 with a clearance sufficient to permit frame Bilto oscillate freely about its pivots 8i.

Carriage rebound check operation It is believed that the operation of the rebound check will be clear from the above description and only a brief summary of the functions will be set out here. Prior to initiation of a tabulating operation, the parts involved are in their normal positions as shown in Figures 1, 3 and 4. In these positions tabulator stop reed 48 is down below the path of any set stops 49 on thecarriage I5, shaft 39 is in its clockwise position, and nose 84 of the rebound check 69 rests against pin 85 of the stop reed 48, thus positioning'the stop nose 88 as in Figure 3, i. e. slightly to the right and rear of a tabulator stop 49. Nose 66 is also very slightly to the left of its support 61 (right in Figure 2). In these positions, the carriage I5 is free to be moved without interference. Upon operation of a tabulator'key 2I, actuator bar 28 is, as set out above, driven to the left to rock shaft 39 counterclockwise and, through link 4! and lever 42, to project stop reed 48 to its upper position wherein its end is positioned to intercept a set one of the tabulator stops 49. Lug 52 of stop reed 48 is drawn to the left by spring 54 to snap over plate 53, see Figure '7, and hold the stop reed 48 projected. Projection of reed 48 will move pin 55 from in' front of nose 84 of the rebound check 68, thereby allowing the weight 88 to rock the rebound check 60 clockwise to the position shown in Figure 5.

A suitably positioned stop 69 may be provided to engage the check frame 89 and so limit forward movement of nose 64 to the desired extent. Such clockwise rocking of the rebound check 58 moves its stop nose 86 to the position shown in Figure 6, that is, more to the rear of the line of tabulator stops 49 than in the normal rest position.

At the end of a tabulating run of the carriage I5, a set stop 49 thereon engages the upper end of stop reed 48 and moves it to the left, right in Figure 10, to displace lug 52 from above plate 58 and freestop reed 48 to the restoring action of its spring 56. The resulting downward movement of stop reed 48 immediately reengages the escapement mechanism to prevent further leftward movement of the carriage I5 after stop reed 48 has dropped below the .pathofstop 49. The abrupt termination of the carriage movement and the natural resilience of the tabulator stop 49 and stop reed 48 tend at this time to impel the carriage back to the right. How- 1 position into the position shown in Figure 8. A

At this time, the stop nose 66 has entered into the path of the tabulator stops 49 as in Figure 9. The rebound of the carriage l5 from stop reed '48 now engages stop 69 with nose 65 and distorts the extended arm 60 carrying stop nose 6!; until the arm til engages the fixed support 61 and prevents further reverse movement of carriage [5. As the total rebound movement of carriage l5 under these conditions is limited to less than one letter space, it is evident that carriage IE will be arrested before rebounding out of the proper letter space and spring drum ll will then urge carriage l5 into the desired tabulated position.

When the carriage I5 is arrested after a long tabulating run by the structure as described above, it may happen that carriage IE will rebound a second time. The rebound check 60 will strike pin 65 with its nose 5 5 and rebound to an effective position only slightly less than the original position shown in Figure 8. By a proper selection of the mass of Weight 63 and the clearance of stop nose 66 from stops 49 in the rest position, the time required for the rebound of check 6!] may be made the same as the time interval between the first and second carriage re bounds and the stop nose 66 will then be efiective to halt the second rebound of carriage [5.

After the carriage has settled in its new position, the rebound check 6!] comes to rest in the position shown in Figure 1 wherein it is out of the path of travel of carriage I5.

As many changes may be made in the specific mechanism as detailed above without departing from the spirit or scope of the invention, it is to be understood that the above description is not to be taken in a limiting sense, the invention to be limited only by the following claims.

What is claimed is:

1. In a typewriter of the like having a movable carriage, means to urge said carriage in one direction, a releasable escapement mechanism to normally restrain said carriage from movement, and tabulating mechanism settable to release said escapement mechanism to free said carriage and to position a stop into the path of a part of said carriage to thereby arrest said car riage at a selected position, said tabulating mechanism being restorable by said carriage at said selected position, a normally ineffective rebound check device to momentarily engage said carriage and prevent reverse movement of said carriage from said selected position, means on said tabulating mechanism operable during restoration of said tabulating mechanism to impel said rebound check device toward effective position, and an inertia means on said rebound check device to impel said device fully into effective position, said inertia means normally acting to maintain said check device in engagement with said tabulating mechanism impelling means wherein said rebound check device is clear of said carriage.

2. In a typewriter having a carriage, settable tabulating mechanism to control tabulation of said carriage'to a given position, normally inefiective means to momentarilyprevent reverse movement of said carriage from said given position, means to restore said tabulating mechanism to an ineffective position, means operated by said tabulating mechanism during said restoring movement to drive said reverse movement preventing means partially to its effective position and an inertia member on said reverse movement preventing means to carry said means into its fully effective position.

In a typewriter having a carriage and tabulating mechanism therefor, said tabulati'ng mechanism being manually controlled for move ment into an effective position and restorable under control of said carriage, means engageable with said carriage to prevent a rebound of said carriage after completion. of a tabulating movement thereof, said means comprising a pivoted bail, a carriage engaging tooth extending from one arm of said. bail, and an inertia member and a driving nose on the crosspiecc of said bail, and means on said tabulating mechanism normally engaging the driving nose of said bail. said bail being urged to position. said driving nose into the return path or" said means on said tabulating mechanism when said tabulating mechanism is set into effective position whereby said means on said tabulating mechanism in its return movement strikes said driving nose of said bail and restores it to normal position, the inertia of said bail and said inertia member thereupon causing said bail to move further in the restoring direction to momentarily engage said carriage engaging tooth with said carriage.

4. In a typewriter having a carriage and tabulating mechanism therefor, said tabulating mechanism being manually controlled for movement into an effective position and restorable under control of said carriage, means engageable with said carriage to prevent a rebound of said carriage after completion of a tabulating movement thereof, said means comprising a pivoted bail, a carriage engaging tooth extending from one arm of said bail, and an inertia member and a driving nose on the crosspiece of said bail, means on said tabulating mechanism normally engaging the driving nose of said bail, said bail being urged to position said driving nose into the return path of said means: on said tabulating mechanism. when said tabulating mechanism is set into effective position whereby said means on said tabulating mechanism in its return movement strikes said driving nose of said bail and restores it to its normal position, the inertia of said bail and said inertia member thereupon causing said bail to move further in the restoring direction to momentarily engage said carriage engaging tooth with said carriage, and a support positioned adjacent said carriage engaging tooth to prevent excessive flexing of said tooth under the impact of said carriage during rebound.

5. A typewriter having a carriage, means to urge said carriage in one direction, a releasable escapement mechanism to restrain said carriage against the urge of said urging means, a tabu lating mechanism settable under manual control to release said carriage from said escapement mechanism and including a stop member positionable in the path of said carriage, said tabulating mechanism being restorable to withdraw said stop member and reengage said escapement mechanism by engagement of said carriage and said stop member whereby said carriage issubjected to forces tending to drive it ina rebounding direction, a rebound preventing means normally clear of said carriage, means 7 on said tabulating mechanism stop member and operative in the return movement of said stop member to engage said rebound preventing means and drive it toward an effective position, and an inertia member on said rebound preventing means to impel said preventing means into a fully effective carriage intercepting position and then return said preventing means to a normal ineffective position in engagement with said means on said tabulating mechanism stop mem her.

6. In a typewriter having a carriage, tabulating mechanism therefor including a projectable stop, stops on said carriage settable into a position cooperable with said projectable stop, a rebound preventing stop normally 'free of said carriage stops, means connected with said rebound pre venting stop to engage a part of said projectable stop and means on said rebound preventing stop to impositively urge said connected means in a direction to engage said connected means with said part of said projectable stop, said tabulating mechanism and projectable stop being settable under manual control to an efiective position and restorable to normal position under control of said carriage whereby said part of said projectable stop is first moved out of engagement with said means connected to said rebound preventing stop, said connected means thereupon moving into the return path of said part of said projectable stop, and thereafter engages said connected means to drive said rebound preventing stop to normal position, said rebound preventing stop being free to then move further to engage said rebound preventing stop with one of the unset stops on said carriage, and a support member adjacent said reboundpreventing stop to arrest said carriage without an excessive fiexure of-said stop. Y

FRED BECKER.-

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Von Reppert July 4, 1944 

